Wind and Solar ENERGY

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Wind and Solar ENERGY

• Alternative Energy Trailer

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Essential Questions.

• Is wind energy a dependable source of
  electricity? Why or why not?
• Is solar energy a dependable source of
  electricity? Why or why not?
• Why are alternative energy resources needed?

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A definition of Solar power.

• Solar power is the technology of obtaining
  usable energy from the light of the Sun. Solar
  energy has been used in many traditional
  technologies for centuries and has come into
  widespread use where other power supplies are
  absent, such as in remote locations and in space.
• Its application is spreading as the environmental
  costs and limited supply of other power sources
  such as fossil fuels are realized.

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Converting solar energy to electricity

• We can change the sunlight directly to
  electricity using solar cells. Solar cells are
  also called photovoltaic cells - or PV cells for
  short - and can be found on many small
  appliances, like calculators, and even on
  spacecraft. They were first developed in the
  1950s for use on U.S. space satellites. They are
  made of silicon, a special type of melted sand.

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• When sunlight strikes the solar cell, electrons
  are knocked loose. They move toward the treated
  front surface. An electron imbalance is created
  between the front and back. When the two surfaces
  are joined by a connector, like a wire, a current
  of electricity occurs between the negative and
  positive sides

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Wind Energy

• As stated by the US Department of Energy
  Our Nation's wind energy resources can provide an
  inexhaustible domestic source of energy. By
  developing these wind resources, we can help
  stimulate rural economic development, displace
  harmful emissions created by traditional fuels,
  and increase our options for low-cost electricity
  generation.

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Wind Energy potential
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How do wind turbines work?

• Simply stated, a wind turbine works the opposite
  of a fan. Instead of using electricity to make
  wind, like a fan, wind turbines use wind to make
  electricity. The wind turns the blades, which
  spin a shaft, which connects to a generator and
  makes electricity. Utility-scale turbines range
  in size from 50 to 750 kilowatts. Single small
  turbines, below 50

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Wind Energy Converters

• What is a wind generator?
• The proper name of a wind generator is actually
  Wind Energy Converter that being a device that
  converts the potential energy in the wind to
  another form of energy. This can either be
  mechanical or electrical. How does the wind
  generator work?When the wind blows, the rotor
  blade stops a percentage of the wind. That
  percentage is what is converted into energy.
  According to physics, the maximum amount of wind
  energy that can be converted is 59.3. This is
  known as the Betz Limit.

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Generators

• How does a generator work?
• Http//www.wvic.com/how-gen-works.htm

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Wind Power Plant

• Three-bladed wind turbines are operated "upwind,"
  with the blades facing into the wind. The other
  common wind turbine type is the two-bladed,
  downwind turbine.

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A working wind turbine
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In conclusion

• A demand for clean, diverse sources of
  electricity, and state and federal incentives to
  stimulate the market also contributed to wind
  energy's growth.

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A small wind turbine example
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Time to answer the Essential Questions.

• Is wind energy a dependable source of
  electricity? Why or why not?
• Is solar energy a dependable source of
  electricity? Why or why not?
• Why are alternative energy resources needed?

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Sources

• http//en.wikipedia.org/wiki/Solar_power on
  1/8/07
• http//www.energyquest.ca.gov/story/chapter15.html
  on 1/8/07
• http//www.eia.doe.gov/kids/energyfacts/sources/re
  newable/solar.html on 1/8/07
• http//www.wyomingnews.com/articles/2007/01/07/new
  s/local_news/03local_01-07-07.txt on 1/8/07
• http//www.fsec.ucf.edu/en/ on 1/8/07
• http//www.nrel.gov/wind/ 1/06
• http//www.nrel.gov/wind/wind_potential.html 1/06
• http//www.wvic.com/how-gen-works.htm 1/06
• http//eereweb.ee.doe.gov/windandhydro/wind_resear
  ch.html 1/6
• http//ww2010.atmos.uiuc.edu/(Gh)/guides/mtr/fw/cr
  ls.rxml
• Tarbuck and Lutgens, Earth Science by Prentice
  Hall, 2006